In corporate and other networks, users may be required to authenticate to a proxy server prior to accessing the Internet. One widely used authentication scheme is Hypertext Transfer Protocol (HTTP) Basic Authentication. In Basic Authentication, a client sends its username and password in unencrypted plaintext to a server, such as, for example, a proxy server. The server authenticates the client and subsequently allows the client access to other resources, such as the Internet. In such a configuration, an attacker can monitor network packets to obtain the username and password of the client, and possibly compromise the security of the network.